Self-locking container



April 17, 1945.

M. 1. WILLIAMSON ET AL SELF-LOCKING CONTAINER 4 Sheets-Sheet l Filed Aug. 19, 1943 6 Marshall L BY VmcemL RPanaone INVENTOR Wl l lamson ATTORNEY April 17, 1945- M. l. wlLLlAMsoN ET AL. 2,373,730

SELF-LOOKING CONTAINER 4 sheets-sheet 2 Filed Aug. 19, 1945 Marshall I.VVllamson B /Vmcen RPa lone THE/R ATTORNEY April 17, 1945. M. l. wlLLlAMsoN ET'AL 2,373,730

' SELF-LOCKING CONTAINER 4 Sheets-Sheet 3 Filed Aug. 19, 1943 April 17, 1945. M. l. WILLIAMSON Ef A1.

SELF-LOCKING CONTAINER Filed Aug. 19, 1943 4 Sheets-Sheet 4 46 INVENToRs MarshaH LWIIIuamson cenRP nralone THEa o N -turned inwardly toward, and,

'provided and set up,

notch-like or shouldered end formations should Patented Apr. 17, 1945 Marshall I. Williamson,

R. Pantalone, Hamden, tional Folding Box Company, Conn., a corporation of New Jersey New Haven, and Vincent Conn., assignors to Na- New"f Haven,

Application August 19, 1943, Serial No. 499,198 5 Claims. (Cl. 229-35) This invention relates to self-locking containers and is particularly directed to containers of the general tray and cover type formed of foldable sheet material, such as paper box board.

In accordance with the invention, the cover part and the tray part of such'a container are so arranged as to automatically inter-lock when fitted together in normal telescopic relationship.

For this purpose, the cover partk and the tray part each comprises complementary end dr other side formations correlated to lock relative to one another when the cover part and the tray part are telescope'd with respect to one another.

An effective complementary formation, Vsay for each of the ,/opposite ends of the cover part, is

:had by providing extensions ofthe side wall panels combined with an extension of the. top wall panel, such extensions of the side Wall panels,

upon setting up the cover part, being respectively in certain embodiments, partly overlapping, one another, the extension of the top wall panel being folded over upon and secured in xed relation to the inwardly turned side extensions, therebfyv giving rise to notch-like or shouldered formations at the opposide ends of the cover part and inwardly thereof.

The complementary formation of the correspondin'g ends of'the tray part may be similarly excepting that the two be located outwardly of the tray.

Preferably, the two opposite top Wall panel extensions of the cover part, and the corresponding extensions of the tray part, are each provided with one or more tabs projecting at the free edges thereof, and the side wall panel extensions of both cover part and tray part are provided either with mutually registering closed slots or mutually interlocking openended slots, or slots produced by infolding of the side wall panel extensions, for receiving such tab Vor tabs, tol thus secure. the notch-like or shouldered end formations in set up condition. 1

The notch-like or shouldered formations of the tray and cover part are so arranged that abutment edge portions are provided intermediate the depths of the respective end wall panels.

The respective cover and tray parts of any emy bodiment of the invention are preferably produced in unassembled flat blank status. the blanks thereof advantageously being" identical, except for the obviously necessary lesser dimensions of the tray part relative to its associated cover part. The blanks may be assembled into setup condition. as and when occasion warrants.

i each other.

When the cover part and tray part are set up and telescopically inter-associated, the abutment edge portions of corresponding notch-like or shouldered formations thereof engage in mutually abutting relationship to automatically lock the two -parts in their telescoped positions relative to In this condition, the end walls of the cover part present an altogether smooth and neat outward appearance, with the inter-locked, notchlike or shouldered formations disposed inwardly thereof. `Similarly, the end walls of the tray part are inwardly smooth and unbroken, the

' inter-locked, notch-like or shouldered formations being disposed outwardly thereof. Thus,

l the vwalls of the container are smooth and untion of the tray part, at a sim/ila'r except for part Sh broken wherever they come in contact with contents of the container as well as wherever they are visible to a purchaser or user Aof the packaged product.

Further features and objects of the invention will be more fully understood from the followingv detail description and the accompanying drawings, in `Which- Fig. 1 is an exploded view, container or the like embodying the invention, a

in perspective, of a portion'of a side of the cover part being broken l away to expose otherwise hidden parts.

Fig. 2 is a detail sectional view on the line 2-2 of Fig. 1. v

Fig. 3 a detail top plan view of one end of the tray part of the container.

Fig. 4 is a detail sectional view on the of Fig. 3. f v

Fig. 5is 'a detail perspective view of an end porstage of setting up the hne 4 4 indicated end of the same.

Fig. 6 illustrates the blank of the cover part of the preferred embodiment of the invention shown in Fig. 1, the blank of the tray part being slightly lesser dimensions. Fig. 'Tis an exploded view of interlocking end part, respecent of the portions of the cover part and tray tively,. of another preferred em invention.'

Fig. 8 is a bottom view of the portion of the tray own-in Fig. 7. Fig.9 illustrates one end fragment of the blank of the cover part of Ithe embodiment of Figs. 7 and 8, the blank of the tray part being of similar formation, but slightly less in dimensions.

Fig/1U is an exploded view, in perspective off/4 another preferred embodiment of the invention.

Fig. 11 is a detail perspective view of an end portion of the tray of Fig. 10, at a, stage of setting up the indicated end of the tray.

Fig. 12 is a detail sectional view on line |2|2 of Fig. 10, where thecover part has been positioned over and is in locking relation with the tray part.

Fig. 13 illustrates the blank of the cover part of the embodiment of Figs. 10, lland 12, andlikewise of the tray part assuming lesser dimensions as compared with the cover part,

Referring to the embodiment illustrated in Figs. 1 through 6, the cover part designated generally 20, is shown of rectangular configuration, comprising a. top panel 2| and side panels 22, 22. The opposite ends of the cover part are shown as each provided with extensions 23, 23, respectively hingedly connected to the side panels 22, 22, and an extension 24 hingedly connected to the top panel 2|. Each top extension 24 is scored as indicated at 25, giving rise to its flange portion 26;also each top extension is provided with a tab 21 projecting' from the parallel free edges of the flange portion 26. Each side extension 23 is shown provided with a slot 28, re-

. ferred to more fully hereinafter.

As appears from Figs. 1 and 2, the cover part is set up by breaking" the indicated score lines, the setting up of each end of the cover part being had by infolding the extensions 23, 23, to project toward one another and to overlap at their terminal portions to effect register of their slots 2B, then folding the top extension 24 and its flange portion 26 to embrace the extensions 23, 23 and inserting the tab 21 within the thus registered slots 28, 28.

'I'he tray part of the embodiment shown in Figs. 1 through 5 may be constituted of panels, i. e. bottom and side panels which correspond generally to the top panel and the side panels of the cover part and are respectively designated by the same reference numbers bearing the sufnx a; however, the parts constituting the opposite end portions of the tray part when set-up are disposed exteriorly thereof, whereas, as above set out, the end formations of the cover part are formed interiorly thereof.

As appears from Figs. 1, 2, 3 and 5, upon insertion of' the tabs 21, 21, of the cover part and of the tabs 21a, 21a, of the tray part, notchlike or shouldered formations are brought about. The edge portions 29, 29 of each notch-like or shouldered formation of the cover part, and the edge portions 29a, 29a of each notch-like or shouldered portion of the tray part are mutually ef fective as locking elements. Such mutual locking effected. by the respective sets of notch-like formations of the opposite ends of the cover part and the tray part is had by abutting engagement between the edge portions 29, 29, of the notchlike formations of the cover part relative to the edges 29a, 29a. of the tray part, and, to accom..

. plish this, each terminal portion 26 of the cover until the locking edge portions 29, 29 thereof pass over and just beyond the locking edge portions 29a, 29a of tle tray part. Thereupon, the notchlike formations of both tray and cover part snap or flex into locked relationship.

It will be observed that each notch-like formation possesses a relatively bulged portion, caused-- respective notch formations, the resiliency of the flexible sheet material of the cover part and of the tray part causes a snap movement in effectl ing the mutually locked relationship, see Fig. 4.

To disengage the cover part from the tray part, a suitable instrument, preferably fiat, such as the blade of a knife, is inserted between the respective-end formations of the tray part and of the associated end formations of the cover part and upon application of force applied to either or both of the cover part and the tray part, the cover part isv separated and released from the tray part.

The embodiment shown in Figs. '7, 8 and 9 corresponds generally to that shown in Figs. 1 through 6. However, the embodiment of Figs. 7, 8 and 9 comprises notch-like end formations respectively interiorly of the cover part formed of extensions 30, 30, at each end of the cover part hingedly connected respectively with the opposite side panels, 3|, 3|; each extension 3U is provided With an open slot such as shown at 32 at the indicated edge. Such notch formation also includes an extension 33 hingedly connected to the top panel 34, having a terminal portion 35 which is provided with two tabs 36, 36. The free edge portions of the terminal portion 35 are indicated 31. In this embodiment, as appearsl from the upper part of Fig. 7 illustrating an end portion of the cover partl 20, upon inter-folding the extensions 30, 30, and folding thereover the top extension 33, the tabs 36, 36, are respectively insertable in the thus registered set of dual slots part is preferably dimensioned slightly less than 4 half the height of the end wall panel 24, whereby the edge portions 29, 29, of the notch-like formations of the coverv part are located ata spacing from the edge of the open side of the cover part slightly greater than one-half the height of ,the

The tray part of the embodiment of Figs. 7, 8 and 9 is shown similarly constituted, the constitutent elements'of the tray part including its exterior notch-like end formations being designated by corresponding reference numbers wit the suffix a. i

It will be noted in the embodiment of Figs. 7 and 8, that three' mutually spaced notch edge portions 31, 31, 31 are presented in the respective endvformations of the cover part, located interiorly of the cover, and a correspondingly three, therewith abutting notch edge portions 31a, 31a, 31a are presented exteriorly of the tray part at its opposite end portions.

aa'ravso shown at 45. The topextension 4I and the respective4 sideextensions 40, 40, at `each end of the cover part are hingedly related by score lines' 44, 44.

The top extension 4l, at each'end of the cover part, is' scored at line 45 (in alignment with the extreme edges of the side extensions 40, 40), giving riseto the terminal portion 46, which is preferably tapered.. as shown, at its side edges. Each terminal portion 46 has a tab ,41,hingedly conl0 nected thereto by score line 48,and each'vtab 41 is provided intermediately-with a series of mutually parallel crease lines 49 Ithreeshown).

The tray part of the embodiment ofFigs. 10

through 13, comprises 'parts corresponding to 15 manner give rise to mutually interlocking notch formations at eachY end interiorly of the cover part and exteriorly of the tray part.l

Taking the tray part of this embodiment as an illustration, it is set up by breaking the indicated score lines hingedly connecting the side panels 22a, 22a, with the bottom panel Zia. This movement of setting up the side panels 22a, 22a, is accompanied by upward movement of the bottom extension 4Ia, as indicated in Fig. 11, with selfinfolding of the respective side extensions a, 35

40a, each upon itself, afforded by its diagonal score line 42a and exteriorly of the contour of the tray part. Each terminal portion 46a is then outwardly folded over its associated infolded side extensions 40a, 40a and locked in notch forma- 40 tion by tucking in its tab 41 (facilitated by its mutually parallel crease lines 48), to embrace and retain the., respective folded side extensions 40a, 40a., The set up tray part 20a is shown in that the edge located at 48a, and formed by the crease 48a. upon inserting the tab 41a into posi-` tion, is disposedat a spacing from the top edge of the open upper side of the tray part lessthan v y one-half of the height of tray'part.

The cover part 20 is set up in the manner similar to that of the tray part 20a, the set up cover part being shown in the upper portion of Fig. 10. The edge 48 of the cover part is thus disposed at a spacing from the top panel 2| less than one- 55 half of the height of the cover part.

As is readily deducible from Fig. 10, and as is shown specifically in Fig. l2 with respect to one end of the assembled and mutually locked cover part 20 and of the tray part 20a, the respective 60 notch formations of the cover part and of the tray part pass one another when the cover part is telescoped upon the tray part until the edge 48 of the cover part clears the edge1 48a of the tray notch formations comes into operation, whereafter the edge 48 of the notch formation of the cover part is locked relative to and by the edge 48a of the notch formation of thetray part.

It is noted that the insets indicated at 42 of 70 each side extension relative to its associated' side panel and top extension of the cover part, similarly with respect to the corresponding insets of the side extensions of the tray part, compensate for the thickness of the top or bottom exten- 75 part, whereupon the resiliency of the two sion when set up. as above described, to present a flush edge at the open .side of the c over part and likewise with regard to the tray part.

This last described embodiment of the invention has the important advantage of water-tight corners.

Wheres the invention is here describedv with respect to certain preferred specific embodiments thereof, it shouldI be understood that various yyieldable sheet material, the cover part being i closely dimensioned with respect to the tray part; the tray part having exteriorly of its opposite end panels and the cover part having interiorly of its opposite end panels juxtaposed mutually locking formations, each end locking formation comprising an extension of said end panel and extensions of the therewith associated side panels, the side panel extensions being folded to overlap one another intermediately of the end panel and the end panel extension being folded to overlap the overlapped portions of the side panel extensions, thereby giving rise to bulging intermediate theend panel, the end panelextension terminating in an intermediately disposed tab and therefrom oppositely extending mutually parallel free ledges, the side panel extensions providing an opening for the reception of the tab and for maintaining such intermediate bulging of the lock formation, the parallel free edges of the juxtaposed end locking formations of the cover extending below the parallel free edges of the end locking formations of the tray, whereby upon telescoping the 'cover partover the tray part the intermedil t f l the lower portlon of Flg. 10 It wm be observed 45 a e bu ging formations and the close dimensionv ing of the container parts effect mutual abutting engagement between the respective associated free edges of the locking formations to thereby lock the cover part relative vto the tray part. y 2. In a self-locking container, the combination of a tray part and a therewith outwardly telescoping cover part, Veach said part comprising yieldable sheet material, the cover part being closely dimensioned with respect to the tray part; the tray part having exteriorly of its opposite end panels and the cover part having interiorly of its opposite end panels juxtaposed mutually locking formations, each end locking formation comprising an extension of such end panel and extensions of the therewith associated side panels, the side panel extensions being folded to. overlap one another centrally of the end panel and the end panel extension being folded to overlap the overlapped portions of the side panel extensions, thereby giving rise to bulging intermediate of the end panel, the end panel extension terminating in aoentrally disposed tab and therefrom opporsitely extending mutually parallel free edges, the side panel extensions providing an opening for the reception of the tab and for maintaining such central lbulging of the lock formation, the parallel free edges of the juxtaposed end locking formations of the cover extending below the parallel free edges of the end locking formations of the tray, whereby upon telescoping the cover part the tray part, having exteriorly of its opposite endI panels and the cover part having interiorly of its opposite end panels juxtaposed mutually locking formations, each end locking` formation comprising an extension of said end panel and extensions of the therewith associated side panels, the side panel extensions being folded to overlap one another intermediately of the end panel and the end panel extension being folded to overlap the overlapped portions of the side extensions, thereby giving rise to bulging intermediate the end panel, the end panel extension terminating in an intermediately disposed tab and therefrom oppositely extending mutually parallel free edges, the side panel extensions being provided with mutually registering slots for the reception of the tab and for maintaining such intermediate bulging of the lock formation, the parallel free edges of the juxtaposed end locking formations of the cover extending below the parallel free edges of the end locking formations of the tray, whereby upon telescoping the cover part over the tray part the intermediate bulging for-l mations and the close dimensioning of the container parts eifect mutual abutting engagement between the respective associated free edges of the locking formations to thereby lock the cover part relative to the tray part.

4. In a self-locking container, the combination of a tray part and a therewith outwardly telescoping cover part, each said part comprising yieldable sheet material, the cover part being'closely dimensioned with respect to the tray part; the tray part having exteriorly of its opposite end panels and the cover part having interiorly of its opposite end panels juxtaposed mutually locking formations, each endlocking formation comprising an extension of such end panel and extensions of the therewith associated side panels, the side panel extensions being folded to overlap one another centrally ofthe end panel and the end panel extension being folded to overlap the overlapped portions of the side panel extensions, thereby giving rise to bulging intermediate of the end panel, the end panel extension terminating in a' centrally disposed tab and therefrom oppositely extending mutually parallel free edges, the side panel extensions being provided with mutually registering slots for the reception of the tab and for maintaining such central bulging of the lock formation, the parallel free edges of the juxtaposed end locking formations of the cover extending below the parallel free edges of the end locking formations 0f the tray, whereby upon telescoping the cover part over the tray part the central bulging formations and the close dimensioning of its container parts effect mutual abutting engagement between the respective associated free edges of the locking formations to thereby lock the cover part relative'to the tray part.

5. In a self-locking container, the combination of a tray zpart and a therewith outwardly telescoping cover part, each said part comprising yieldable sheet material, the cover part being closely dimensioned with respect to the tray part; the tray part having exteriorly of its opposite end panels and the cover part having interiorly of its opposite end panels juxtaposed mutually locking formations, each end locking formation comprising an extension at the outward free edge of said end panel and extensions of the therewith associated side panels, the side panel extensions being folded to overlap one another intermediately of the end panel and the end panel extension being folded to overlap the overlapped portions of the side panel extensions, thereby giving rise to bulging intermediate the end panel, the end panel extension terminating in an intermediately disposed tab and therefrom oppositely extending mutually parallel free edges, the side panel extensions providing an opening for the reception of the tab and for maintaining such intermediate bulging of the lock formation, the parallel free edges of the juxtaposed end locking formations of the cover extending below the parallel free edges of the end locking formations of the tray, whereby upon telescoplng the cover part 'over the tray part the intermediate bulging for- 

